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Wu Q, Huang X, Liu R, Yang X, Xiao G, Jiang N, Weitz DA, Song Y. Multichannel Multijunction Droplet Microfluidic Device to Synthesize Hydrogel Microcapsules with Different Core-Shell Structures and Adjustable Core Positions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1950-1960. [PMID: 37991242 DOI: 10.1021/acs.langmuir.3c02579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Core-shell hydrogel microcapsules have sparked great interest due to their unique characteristics and prospective applications in the medical, pharmaceutical, and cosmetic fields. However, complex synthetic procedures and expensive costs have limited their practical application. Herein, we designed and prepared several multichannel and multijunctional droplet microfluidic devices based on soft lithography for the effective synthesis of core-shell hydrogel microcapsules for different purposes. Additionally, two different cross-linking processes (ultraviolet (UV) exposure and interfacial polymerization) were used to synthesize different types of core-shell structured hydrogel microcapsules. Hydrogel microcapsules with gelatin methacryloyl (GelMA) as the core and polyacrylamide (PAM) as the thin shell were synthesized using UV cross-linking. Using an interfacial polymerization process, another core-shell structured microcapsule with GelMA as the core and Ca2+ cross-linked alginate with polyethylenimine (PEI) as the shell was constructed, and the core diameter and total droplet diameter were flexibly controlled by carving. Noteworthy, these hydrogel microcapsules exhibit stimuli-responsiveness and controlled release ability. Overall, a novel technique was developed to successfully synthesize various hydrogel microcapsules with core-shell microstructures. The hydrogel microcapsules possess a multilayered structure that facilitates the coassembly of cells and drugs, as well as the layered assembly of multiple drugs, to develop synergistic therapeutic regimens. These adaptable and controllable hydrogel microdroplets shall held great promise for multicell or multidrug administration as well as for high-throughput drug screening.
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Affiliation(s)
- Qiong Wu
- Center for Modern Physics Technology, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Xing Huang
- Physics Department, School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Mechanical Engineering, Hangzhou City University, Hangzhou 310015, China
- Zhejiang Provincial Engineering Center of Integrated Manufacturing Technology and Intelligent Equipment, Hangzhou City University, Hangzhou 310015, China
| | - Ran Liu
- Center for Modern Physics Technology, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
- Zhengzhou Tianzhao Biomedical Technology Company Ltd., Zhengzhou 451450, China
- Key Laboratory of Pulsed Power Translational Medicine of Zhejiang Province, Hangzhou 310003, China
| | - Xinzhu Yang
- Center for Modern Physics Technology, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
- Zhengzhou Tianzhao Biomedical Technology Company Ltd., Zhengzhou 451450, China
- Key Laboratory of Pulsed Power Translational Medicine of Zhejiang Province, Hangzhou 310003, China
| | - Gao Xiao
- Physics Department, School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
- Department of Environmental Science and Engineering, College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350108, China
| | - Nan Jiang
- Physics Department, School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
- West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, China
- JinFeng Laboratory, Chongqing 401329, China
| | - David A Weitz
- Physics Department, School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Yujun Song
- Center for Modern Physics Technology, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
- Physics Department, School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
- Zhengzhou Tianzhao Biomedical Technology Company Ltd., Zhengzhou 451450, China
- Key Laboratory of Pulsed Power Translational Medicine of Zhejiang Province, Hangzhou 310003, China
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2
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Mercer IG, Italiano AN, Gazaryan IG, Steiner AB, Kazakov SV. Degradation Kinetics of Disulfide Cross-Linked Microgels: Real-Time Monitoring by Confocal Microscopy. Gels 2023; 9:782. [PMID: 37888355 PMCID: PMC10606370 DOI: 10.3390/gels9100782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/14/2023] [Accepted: 09/21/2023] [Indexed: 10/28/2023] Open
Abstract
Although biodegradable microgels represent a useful drug delivery system, questions remain regarding the kinetics of gel degradation and subsequent drug release. Spherical microgels (~Ø10-300 µm) were synthesized using an inverse suspension polymerization method. Specifically, acrylamide and acrylonitrile monomers were thermally co-polymerized with N,N'-bis(acryloyl)cystamine as a cross-linker with disulfide bridges. The kinetics and mechanism of degradation of these cross-linked, degradable, fluorescently labeled microgels (PAAm-AN-BAC-FA) were quantitatively studied under confocal microscopy at various concentrations of glutathione (reducing agent) ranging from 0.06 to 91.8 mM. It was found that polymer network degradation via the cleavage of disulfide bonds was accompanied by two overlapping processes: diffusion-driven swelling and dissolution-driven erosion. A slow increase in microgel size (swelling) resulted from partial de-cross-linking in the bulk of the microgel, whereas a faster decrease in fluorescence intensity (erosion) resulted from the complete cleavage of disulfide bonds and the release of uncleaved polymeric chains from the microgel immediate surface into the solution. Swelling and erosion exhibited distinct kinetics and characteristic times. Importantly, the dependence of kinetics on glutathione concentration for both swelling and erosion suggests that degradation would occur faster in cancer cells (higher concentration of reductants) than in normal cells (lower concentration of reductants), such that drug release profiles would be correspondingly different. A greater comprehension of microgel degradation kinetics would help in (i) predicting the drug release profiles for novel multifunctional drug delivery systems and (ii) using redox-sensitive degradable hydrogel particles to determine the concentrations of reducing agents either in vitro or in vivo.
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Affiliation(s)
- Iris G. Mercer
- Department of Chemistry and Physical Sciences, Pace University, Pleasantville, NY 10570, USA; (I.G.M.); (A.N.I.); (I.G.G.)
| | - Angelina N. Italiano
- Department of Chemistry and Physical Sciences, Pace University, Pleasantville, NY 10570, USA; (I.G.M.); (A.N.I.); (I.G.G.)
| | - Irina G. Gazaryan
- Department of Chemistry and Physical Sciences, Pace University, Pleasantville, NY 10570, USA; (I.G.M.); (A.N.I.); (I.G.G.)
| | - Aaron B. Steiner
- Department of Biology, Pace University, Pleasantville, NY 10570, USA;
| | - Sergey V. Kazakov
- Department of Chemistry and Physical Sciences, Pace University, Pleasantville, NY 10570, USA; (I.G.M.); (A.N.I.); (I.G.G.)
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3
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Kehren D, Lopez CM, Theiler S, Keul H, Möller M, Pich A. Multicompartment aqueous microgels with degradable hydrophobic domains. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.03.074] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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4
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Sun M, Wong JY, Nugraha B, Ananthanarayanan A, Liu Z, Lee F, Gupta K, Fong EL, Huang X, Yu H. Cleavable cellulosic sponge for functional hepatic cell culture and retrieval. Biomaterials 2019; 201:16-32. [DOI: 10.1016/j.biomaterials.2019.01.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 01/18/2019] [Accepted: 01/20/2019] [Indexed: 12/27/2022]
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5
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Madasamy K, Shanmugam VM, Velayutham D, Kathiresan M. Reversible 2D Supramolecular Organic Frameworks encompassing Viologen Cation Radicals and CB[8]. Sci Rep 2018; 8:1354. [PMID: 29358634 PMCID: PMC5778010 DOI: 10.1038/s41598-018-19739-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 12/07/2017] [Indexed: 01/04/2023] Open
Abstract
Reversible 2D supramolecular organic frameworks encompassing branched viologen architectures and cucurbit[8]uril (CB[8]) were constructed and investigated. UV-vis investigation clearly indicates the formation and intermolecular dimerization of monocation radicals and their encapsulation into the hydrophobic CB[8] cavity which is further complemented by EPR (electron paramagnetic resonance) spectroscopy. Particle size measurements by dynamic light scattering method showed particle sizes in the range of several µm indicating larger aggregates. Zeta potential measurements suggested the instability of these particles and their tendency to form aggregates. TEM (transmission electron microscope) analysis further revealed the formation of supramolecular polymer (monocation radical with cucurbit[8]uril) whose diameter were in the range of several µm as indicated by DLS measurements; however the oxidized form, i.e., the viologen dication with cucurbit[8]uril showed dotted spots in the range of sub nanometer level. The internal periodicities of the supramolecular polymers were analyzed by SAXs (small angle X-ray scattering) measurements. Additionally, we have demonstrated that these supramolecular organic frameworks can be depolymerized by oxidation in air and again can be polymerized (intermolecular radical dimerization) by reduction under inert atmosphere demonstrating that these systems will be of broad interest.
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Affiliation(s)
- Kanagaraj Madasamy
- Electroorganic Division, CSIR-Central Electrochemical Research Institute, Karaikudi, 630003, Tamil Nadu, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Electrochemical Research Institute, Karaikudi, 630003, Tamil Nadu, India
| | | | - David Velayutham
- Electroorganic Division, CSIR-Central Electrochemical Research Institute, Karaikudi, 630003, Tamil Nadu, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Electrochemical Research Institute, Karaikudi, 630003, Tamil Nadu, India
| | - Murugavel Kathiresan
- Electroorganic Division, CSIR-Central Electrochemical Research Institute, Karaikudi, 630003, Tamil Nadu, India.
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Electrochemical Research Institute, Karaikudi, 630003, Tamil Nadu, India.
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6
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Lu J, Zhou F, Li L, Zhang Z, Meng F, Zhou N, Zhu X. Novel cyclic azobenzene-containing vesicles: photo/reductant responsiveness and potential applications in colon disease treatment. RSC Adv 2016. [DOI: 10.1039/c6ra12751g] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The vesicles formed by an amphiphilic copolymer with cyclic azobenzene pendants revealed higher drug loading content and better photo/reductant responsiveness than an analogue of the amphiphilic copolymer with linear azobenzene units.
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Affiliation(s)
- Jinjie Lu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Feng Zhou
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Lishan Li
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Zhengbiao Zhang
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Fenghua Meng
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Nianchen Zhou
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
| | - Xiulin Zhu
- State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials
- Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application
- College of Chemistry
- Chemical Engineering and Materials Science
- Soochow University
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7
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Karabacak RB. Emulsifier-free poly[2-(diethylamino)ethyl methacrylate] microgels with cationic quaternary ammonium monomers. J Appl Polym Sci 2015. [DOI: 10.1002/app.43196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- R. Bengü Karabacak
- Department of Chemistry; Anadolu University; Eskişehir 26470 Turkey
- Göztepe Mh; Dumlupınar Cd. No: 109/8 Eskişehir Turkey
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8
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Grant N, Wu H, Zhang H. Reduction-Controlled Release of Organic Nanoparticles from Disulfide Cross-linked Porous Polymer. Ind Eng Chem Res 2013. [DOI: 10.1021/ie403001r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Neil Grant
- Department
of Chemistry, University of Liverpool, Oxford Street, Liverpool, L69 7ZD, United Kingdom
| | - Hong Wu
- Department
of Pharmaceutical Chemistry and Pharmaceutical Analysis, School of
Pharmacy, Fourth Military Medical University, Xi’an 710032, China
| | - Haifei Zhang
- Department
of Chemistry, University of Liverpool, Oxford Street, Liverpool, L69 7ZD, United Kingdom
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9
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Morse AJ, Armes SP, Mills P, Swart R. Stopped-flow kinetics of pH-responsive polyamine latexes: how fast is the latex-to-microgel transition? LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15209-15216. [PMID: 24251539 DOI: 10.1021/la403626s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Four poly(ethylene glycol)-stabilized polyamine latexes, namely, poly(2-vinylpyridine) (P2VP), poly(2-(tert-butylamino)ethyl methacrylate) (PTBAEMA), poly(2-(diethylamino)ethyl methacrylate) (PDEA), and poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) were prepared via emulsion copolymerization using divinylbenzene (DVB) as a cross-linker at 0.80 mol % for all formulations. According to dynamic light scattering studies, the resulting latexes were near-monodisperse and had approximately constant hydrodynamic diameters of 205-220 nm at pH 10; a latex-to-microgel transition was observed at around the respective pKa of each polyamine on addition of acid. The kinetics of swelling of each latex was investigated by the pH-jump method using a commercial stopped-flow instrument. The most rapid swelling was observed for the P2VP latex, which exhibited a characteristic swelling time (t*) of 5 ms. The corresponding t* values for PTBAEMA and PDEA were 25 and 35 ms, respectively, whereas the PDPA particles exhibited significantly slower swelling kinetics (t* = 180 ms). These t* values could not be correlated with either the latex Tg or the polyamine pKa. However, there is a positive correlation between t* and the repeat unit mass of the amine monomer, which suggests that the cationic charge density of the protonated polymer chains may influence the kinetics of swelling. Alternatively, the observed differences in swelling kinetics may simply reflect subtle differences in the DVB cross-link density, with more uniformly cross-linked latexes being capable of responding more quickly to a pH jump. The kinetics of deswelling for the corresponding microgel-to-latex transition was also briefly investigated for the PTBAEMA and P2VP particles. In both cases, much slower rates of deswelling were observed. This suggests that a latexlike "skin" is formed on the outer surface of the microgel particles during their deprotonation, which significantly retards the excretion of both salt and water.
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Affiliation(s)
- A J Morse
- Department of Chemistry, University of Sheffield , Brook Hill, Sheffield S3 7HF, U.K
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10
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Polotsky AA, Plamper FA, Borisov OV. Collapse-to-Swelling Transitions in pH- and Thermoresponsive Microgels in Aqueous Dispersions: The Thermodynamic Theory. Macromolecules 2013. [DOI: 10.1021/ma401402e] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Alexey A. Polotsky
- Institute of Macromolecular Compounds of the Russian Academy of Sciences, 31 Bolshoy pr., 199004 St.-Petersburg, Russia
| | - Felix A. Plamper
- Physikalische
Chemie II, RWTH Aachen University, 52056 Aachen, Germany
| | - Oleg V. Borisov
- Institute of Macromolecular Compounds of the Russian Academy of Sciences, 31 Bolshoy pr., 199004 St.-Petersburg, Russia
- St.Petersburg National Research University of Information Technologies, Mechanics and Optics, 197101, Kronverkskiy
pr., 49, St.Petersburg, Russia
- Institut des Sciences Analytiques et de Physico-Chimie pour l’Environnement et les Matériaux, UMR 5254 CNRS/UPPA, Pau, France
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11
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Santillán R, Nieves E, Alejandre C, Gómez-Yañez C, del Río J, Dorantes-Rosales H, Navarro-Clemente M, Corea M. Synthesis of highly carboxylated latex particles using a power feed process. J IND ENG CHEM 2013. [DOI: 10.1016/j.jiec.2012.12.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Månsson R, Frenning G, Malmsten M. Factors Affecting Enzymatic Degradation of Microgel-Bound Peptides. Biomacromolecules 2013; 14:2317-25. [DOI: 10.1021/bm400431f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ronja Månsson
- Department
of Pharmacy, Uppsala University, P.O. Box
580, SE-751 23 Uppsala, Sweden
| | - Göran Frenning
- Department
of Pharmacy, Uppsala University, P.O. Box
580, SE-751 23 Uppsala, Sweden
| | - Martin Malmsten
- Department
of Pharmacy, Uppsala University, P.O. Box
580, SE-751 23 Uppsala, Sweden
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13
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Reversible disulphide formation in polymer networks: A versatile functional group from synthesis to applications. Eur Polym J 2013. [DOI: 10.1016/j.eurpolymj.2013.03.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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14
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One-step synthesis of pH-sensitive poly(Acrylamide-co-Sodium Acrylate) beads with core–shell structure. REACT FUNCT POLYM 2013. [DOI: 10.1016/j.reactfunctpolym.2012.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Klinger D, Landfester K. Stimuli-responsive microgels for the loading and release of functional compounds: Fundamental concepts and applications. POLYMER 2012. [DOI: 10.1016/j.polymer.2012.08.053] [Citation(s) in RCA: 173] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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16
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Hansson P, Bysell H, Månsson R, Malmsten M. Peptide–Microgel Interactions in the Strong Coupling Regime. J Phys Chem B 2012; 116:10964-75. [DOI: 10.1021/jp306121h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Per Hansson
- Department
of Pharmacy, Uppsala University, P.O. Box
580, SE-751 23 Uppsala, Sweden
| | - Helena Bysell
- Department
of Pharmacy, Uppsala University, P.O. Box
580, SE-751 23 Uppsala, Sweden
| | - Ronja Månsson
- Department
of Pharmacy, Uppsala University, P.O. Box
580, SE-751 23 Uppsala, Sweden
| | - Martin Malmsten
- Department
of Pharmacy, Uppsala University, P.O. Box
580, SE-751 23 Uppsala, Sweden
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17
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Yang B, Lu Y, Luo G. Controllable Preparation of Polyacrylamide Hydrogel Microspheres in a Coaxial Microfluidic Device. Ind Eng Chem Res 2012. [DOI: 10.1021/ie3004013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bodong Yang
- The State Key
Laboratory of Chemical Engineering, Department
of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yangcheng Lu
- The State Key
Laboratory of Chemical Engineering, Department
of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Guangsheng Luo
- The State Key
Laboratory of Chemical Engineering, Department
of Chemical Engineering, Tsinghua University, Beijing 100084, China
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18
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Rikkou-Kalourkoti M, Loizou E, Porcar L, Matyjaszewski K, Patrickios CS. End-linked, amphiphilic, degradable polymer conetworks: synthesis by sequential atom transfer radical polymerization using a bifunctional, cleavable initiator. Polym Chem 2012. [DOI: 10.1039/c1py00349f] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
End-linked amphiphilic conetworks prepared using an ATRP bifunctional, bis(hemiacetal ester) initiator were hydrolyzed by HCl, yielding novel amphiphilic star copolymers.
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Affiliation(s)
| | - Elena Loizou
- Department of Chemistry
- University of Cyprus
- Nicosia
- Cyprus
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19
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Effects of peptide cyclization on the interaction with oppositely charged microgels. Colloids Surf A Physicochem Eng Asp 2011. [DOI: 10.1016/j.colsurfa.2011.01.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Microgels and microcapsules in peptide and protein drug delivery. Adv Drug Deliv Rev 2011; 63:1172-85. [PMID: 21914455 DOI: 10.1016/j.addr.2011.08.005] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 08/16/2011] [Accepted: 08/30/2011] [Indexed: 11/20/2022]
Abstract
The present review focuses on the interaction of microgels and microcapsules with biological macromolecules, particularly peptides and proteins, as well as drug delivery applications of such systems. Results from recent studies on factors affecting peptide/protein binding to, and release from, microgels and related systems are discussed, including effects of network properties, as well as protein aggregation, peptide length, hydrophobicity and charge (distributions), secondary structure, and cyclization. Effects of ambient conditions (pH, ionic strength, temperature, etc.) are also discussed, all with focus on factors of importance for the performance of microgel and microcapsule delivery systems for biomacromolecular drugs.
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21
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Alf ME, Hatton TA, Gleason KK. Novel N-isopropylacrylamide based polymer architecture for faster LCST transition kinetics. POLYMER 2011. [DOI: 10.1016/j.polymer.2011.07.051] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Rikkou MD, Patrickios CS. Polymers prepared using cleavable initiators: Synthesis, characterization and degradation. Prog Polym Sci 2011. [DOI: 10.1016/j.progpolymsci.2011.01.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Preparation of thermoresponsive and pH-sensitivity polymer magnetic hydrogel nanospheres as anticancer drug carriers. Colloids Surf B Biointerfaces 2011; 88:593-600. [PMID: 21871786 DOI: 10.1016/j.colsurfb.2011.07.048] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 07/11/2011] [Accepted: 07/21/2011] [Indexed: 12/16/2022]
Abstract
In this work, a novel thermo and pH responsive magnetic hydrogel nanosphere poly(N-isopropylacrylamide-co-acrylic acid)/Fe(3)O(4) (poly(NIPAAm-co-AA)/Fe(3)O(4)) has been successfully prepared. The magnetic hydrogel nanospheres with thermo and pH-sensitivity were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared-spectrometer (FT-IR), UV-vis absorption spectroscopy, and vibrating sample magnetometer (VSM). The magnetic hydrogel nanospheres exhibited uniform sphere structures and superparamagnetic property. Finally, the drug loading capacities and the releasing behavior of the magnetic hydrogel nanospheres were investigated with doxorubicin hydrochloride (DOX) as an anticancer drug model. The resulting magnetic hydrogel nanospheres exhibited high encapsulation efficiency (95%) to DOX under an appropriate condition. In vitro release experiments revealed that release was faster at pH 5.3 (37°C) than at pH 7.4 (25°C) or pH 7.4 (37°C). The DOX-loaded magnetic hydrogel nanospheres also showed enhanced anticancer effect compared with the free drug in vitro. These presented results suggested that the magnetic hydrogel nanospheres have a potential as tumor targeting drug carrier.
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24
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Mejac I, Tran CD. Visualizing the Effect of Gold Nanocages on Absorption, Imaging, and Lower Critical Solution Temperature Phase Transition of Individual Poly(NiPAM)-Based Hydrogel Particles by Near Infrared Multispectral Imaging Microscopy. Anal Chem 2011; 83:3520-7. [DOI: 10.1021/ac103354z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Irena Mejac
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201, United States
| | - Chieu D. Tran
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201, United States
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25
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Månsson R, Bysell H, Hansson P, Schmidtchen A, Malmsten M. Effects of Peptide Secondary Structure on the Interaction with Oppositely Charged Microgels. Biomacromolecules 2010; 12:419-24. [DOI: 10.1021/bm101165e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ronja Månsson
- Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden, and Section of Dermatology and Venerology, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Helena Bysell
- Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden, and Section of Dermatology and Venerology, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Per Hansson
- Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden, and Section of Dermatology and Venerology, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Artur Schmidtchen
- Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden, and Section of Dermatology and Venerology, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
| | - Martin Malmsten
- Department of Pharmacy, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden, and Section of Dermatology and Venerology, Department of Clinical Sciences, Lund University, SE-221 84 Lund, Sweden
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Malmsten M, Bysell H, Hansson P. Biomacromolecules in microgels — Opportunities and challenges for drug delivery. Curr Opin Colloid Interface Sci 2010. [DOI: 10.1016/j.cocis.2010.05.016] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Mejac I, Park HH, Bryan WW, Lee TR, Tran CD. Visualizing the Lower Critical Solution Temperature Phase Transition of Individual Poly(Nipam)-Based Hydrogel Particles Using Near-Infrared Multispectral Imaging Microscopy. Anal Chem 2010; 82:1698-704. [DOI: 10.1021/ac902099d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Irena Mejac
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201, Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77204
| | - Hye-Hun Park
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201, Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77204
| | - William W. Bryan
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201, Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77204
| | - T. Randall Lee
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201, Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77204
| | - Chieu D. Tran
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, Wisconsin 53201, Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77204
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Saphier S, Rosner A, Brandeis R, Karton Y. Gastro intestinal tracking and gastric emptying of solid dosage forms in rats using X-ray imaging. Int J Pharm 2010; 388:190-5. [PMID: 20079410 DOI: 10.1016/j.ijpharm.2010.01.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 12/28/2009] [Accepted: 01/06/2010] [Indexed: 01/28/2023]
Abstract
The aim of this research was to study the gastrointestinal transit and gastric emptying of non-disintegrating solid dosage forms in rats using X-ray imaging. Commercial gelatin minicapsules were filled with barium sulfate and enterically coated using Eudragit S100. The capsules were administered orally to rats followed by a solution of iodine based contrast agent iopromide. Images were obtained using a standard X-ray camera and digital film processing. Capsules were followed through the GI tract from the stomach to the small intestine, cecum and large intestine and the capsule location could be easily identified. Gastric emptying of different sized capsules was studied. The effect of fasting and time of administration on gastric retention was also studied. It was found that shortened capsules of 3.5 and 4.8mm length were emptied from the stomach whereas the commercial length 7.18mm capsules were retained. Surprisingly, 2.5h post administration more rats retained the capsules in the stomach in the fasted state than in the fed state. We found that X-ray imaging can be used for simple visualization and localization of solid dosage forms in rats in the fed state using shortened commercial minicapsules on rats.
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Affiliation(s)
- Sigal Saphier
- The Department of Organic Chemistry, Israel Institute for Biological Research, Ness-Ziona, Israel.
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Non-Fouling Character of Poly[2-(methacryloyloxy)ethyl Phosphorylcholine]-Modified Gold Surfaces Fabricated by the âGrafting toâ Method: Comparison of its Protein Resistance with Poly(ethylene glycol)-Modified Gold Surfaces. Macromol Rapid Commun 2009; 30:2136-40. [DOI: 10.1002/marc.200900484] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 08/18/2009] [Indexed: 11/07/2022]
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30
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Yoshida H, Klinkhammer K, Matsusaki M, Möller M, Klee D, Akashi M. Disulfide-Crosslinked Electrospun Poly(γ
-glutamic acid) Nonwovens as Reduction-Responsive Scaffolds. Macromol Biosci 2009; 9:568-74. [DOI: 10.1002/mabi.200800334] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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31
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Synthesis and investigation of swelling behavior of new agar based superabsorbent hydrogel as a candidate for agrochemical delivery. JOURNAL OF POLYMER RESEARCH 2009. [DOI: 10.1007/s10965-009-9270-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Niu J, Liu Z, Fu L, Shi F, Ma H, Ozaki Y, Zhang X. Surface-imprinted nanostructured layer-by-layer film for molecular recognition of theophylline derivatives. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11988-11994. [PMID: 18788771 DOI: 10.1021/la802165f] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In this article we report the introduction of the cooperativity of various specific interactions combined with photo-cross-linking of the interlayers to yield binding sites that can realize better selectivity and imprinting efficiency of a surface molecularly imprinted LbL film (SMILbL), thus providing a new approach toward fabrication of nanostructured molecularly imprinted thin films. It involves preassembly of poly(acrylic acid) (PAA) conjugated of the theophylline residue template via a disulfide bridge, denoted as PAAtheo 15, in solution, and layer-by-layer (LbL) assembly of PAAtheo 15 and a positively charged photoreactive diazo resin (DAR) to form multilayer thin film with designed architecture. After photo-cross-linking of the film and template removal, binding sites specific to 7-(beta-hydroxyethyl)theophylline (Theo-ol) molecules are introduced within the film. Binding assay demonstrates that the SMILbL has a high selectivity of SMILbL to Theo-ol over caffeine. A control experiment demonstrates that the selectivity of SMILbL derives from nanostructured recognition sites among the layers. The imprinting amount per unit mass of the film can be 1 order of magnitude larger than that of the conventional bulk molecular imprinting systems. As this concept of construction SMILbL can be easily extended to the other molecules by the following similar protocol: its applications in building many other different molecular recognition systems are greatly anticipated.
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Affiliation(s)
- Jia Niu
- Key Laboratory of Organic Optoelectronics & Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, People's Republic of China
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Bronich TK, Bontha S, Shlyakhtenko LS, Bromberg L, Hatton TA, Kabanov AV. Template-assisted synthesis of nanogels from Pluronic-modified poly(acrylic acid). J Drug Target 2008; 14:357-66. [PMID: 17092836 DOI: 10.1080/10611860600833781] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
A series of novel polymeric nanogels with core-shell morphology was developed. Block ionomer complexes of comb-graft poly(ethylene oxide)-b-poly(polypropylene oxide)-b-poly(ethylene oxide)-g-poly(acrylic acid) copolymers (Pluronic-PAA) and divalent metal cations were utilized as micellar templates for the synthesis of nanogels with sizes ranging from 100 to 200 nm in diameter. The Pluronic-PAA nanogels were confirmed to possess ionic cross-linked PAA cores and flexible hydrophilic shells from the Pluronic copolymer chains. The ionic character of the core provided for pH-dependent swelling/collapse behavior of the nanogels. These prepared nanogels are expected to be of utility as carriers for charged therapeutic or diagnostic agents.
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Affiliation(s)
- Tatiana K Bronich
- Department of Pharmaceutical Sciences and Center for Drug Delivery and Nanomedicine, College of Pharmacy, University of Nebraska Medical Center, 985830 Nebraska Medical Center, Omaha, NE 68198-5830, USA.
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35
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Yin J, Dupin D, Li J, Armes SP, Liu S. pH-induced deswelling kinetics of sterically stabilized poly(2-vinylpyridine) microgels probed by stopped-flow light scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:9334-40. [PMID: 18642939 DOI: 10.1021/la8014282] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Near-monodisperse, sterically stabilized poly(2-vinylpyridine) (P2VP) microgels were synthesized by emulsion polymerization. These particles exhibited completely reversible pH-responsive swelling/deswelling behavior in aqueous solution. Stopped-flow light scattering was employed to investigate the kinetics of pH-induced deswelling in highly dilute dispersions. Upon a pH jump from 2 to various final solution pH values (>or=5.4), the scattered light intensity of an aqueous dispersion of a 1,960 nm microgel exhibited an abrupt initial increase, followed by a gradual decrease to the final equilibrium value. The whole microgel-to-latex deswelling process occurred over time scales of approximately 0.5-1.0 s, which is much slower than the kinetics for latex-to-microgel swelling. The microgel deswelling kinetics depends on the final pH, with a higher final pH leading to a faster rate of shrinkage. Close inspection of the deswelling kinetics during the early stages (<0.2 s) revealed that initial microgel collapse occurred within approximately 50 ms, with more rapid transitions being observed when higher final pH values were targeted. Addition of external salt significantly accelerates the kinetics of deswelling. Systematic studies of the microgel-to-latex transition for a series of six near-monodisperse P2VP particles (with swollen microgel diameters ranging from 1270 to 4230 nm) has also been investigated. The characteristic deswelling time for initial microgel collapse, tau deswell, correlated fairly well with the initial swollen microgel radius, R, in agreement with the Tanaka equation. Moreover, the collective diffusion coefficient of the gel network, D, calculated from the slope of the tau deswell- R (2) curve, was of the order of 10 (-7) cm (2) s (-1).
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Affiliation(s)
- Jun Yin
- Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
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36
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Abstract
Oral administration of anticancer agents is preferred by patients for its convenience and potential for use in outpatient and palliative setting. In addition, oral administration facilitates a prolonged exposure to the cytotoxic agents. Enhancement of bioavailability of emerging cytotoxic agents is a pre-requisite for successful development of oral modes of cancer treatment. Over the last decade, our studies have focused specifically on the utilization of large (MW>10(5)) and non-degradable polymers in oral chemotherapy. A family of block-graft copolymers of the poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) Pluronic(R) polyethers and poly(acrylic acid) (PAA) bound by carbon-carbon bonds emerged, wherein both polymeric components are generally recognized as safe. Animal studies with Pluronic-PAA copolymers demonstrated that these molecules are excreted when administered orally and do not absorb into the systemic circulation. The Pluronic-PAA copolymers are surface-active and self-assemble, at physiological pH, into intra- and intermolecular micelles with hydrophobic cores of dehydrated PPO and multilayered coronas of hydrophilic PEO and partially ionized PAA segments. These micelles efficiently solubilize hydrophobic drugs such as paclitaxel and steroids and protect molecules such as camptothecins from the hydrolytic reactions. High surface activity of the Pluronic-PAA copolymers in water results in interactions with cell membranes and suppression of the membrane pumps such as P-glycoprotein. The ionizable carboxyls in the micellar corona facilitate mucoadhesion that enhances the residence time of the micelles and solubilized drugs in the gastrointestinal tract. Large payloads of the Pluronic-PAA micelles with weakly basic and water-soluble drugs such as doxorubicin and its analogs, mitomycin C, mitoxantrone, fluorouracil, and cyclophosphamide are achieved through electrostatic interactions with the micellar corona. Mechanical and physical properties of the Pluronic-PAA powders, blends, and micelles allow for formulation procedures where an active is simply dispersed into an aqueous Pluronic-PAA micellar formulation followed by optional lyophilization and processing into a ready dosage form. We review a number of in vivo and in vitro experiments demonstrating that that the oral administration of the cytotoxics formulated with the Pluronic-PAA copolymer micelles results in enhanced drug bioavailability.
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37
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Bai D, Hardwick CL, Berron BJ, Jennings GK. Kinetics of pH Response for Copolymer Films with Dilute Carboxylate Functionality. J Phys Chem B 2007; 111:11400-6. [PMID: 17824686 DOI: 10.1021/jp0734023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have investigated the effects of film composition and thickness on the rate of pH-induced response of a copolymer film containing predominately polymethylene with randomly distributed carboxylic acid side groups (denoted as PM-CO2H). These responsive films are prepared directly onto a gold electrode surface by surface-catalyzed polymerization and subsequent hydrolysis. We measured electrochemical impedance at fixed frequency (100 Hz) to monitor the barrier properties of the polymer film during a step change in pH. At a 1-3% molar acid content, the copolymer films exhibit a 2 order of magnitude change in impedance at 100 Hz when the contacting solution pH changes from 11 to 4 (or 4 to 11). For all films, the rate of protonation is slower than that of ionization, consistent with a more gradual transfer of protons through an increasingly hydrophobic film at the outermost nanometers during the protonation step. Increased acid content within the film accelerates both the rate of protonation and ionization. Thinner films (50 nm) with the same acid content show faster response rate in both directions, since water and ions have a shorter transfer path. A large and reversible pH response was obtained for all films studied, but selection of appropriate film composition and thickness can greatly influence the rate of response.
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Affiliation(s)
- Dongshun Bai
- Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA
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Li C, Madsen J, Armes SP, Lewis AL. A new class of biochemically degradable, stimulus-responsive triblock copolymer gelators. Angew Chem Int Ed Engl 2007; 45:3510-3. [PMID: 16634101 DOI: 10.1002/anie.200600324] [Citation(s) in RCA: 219] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Chengming Li
- Dainton Building, Department of Chemistry, University of Sheffield, Brook Hill, Sheffield, South Yorkshire, S3 7HF, UK
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39
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Hu L, Chu LY, Yang M, Wang HD, Hui Niu C. Preparation and characterization of novel cationic pH-responsive poly(-dimethylamino ethyl methacrylate) microgels. J Colloid Interface Sci 2007; 311:110-7. [PMID: 17397857 DOI: 10.1016/j.jcis.2007.02.063] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 02/18/2007] [Accepted: 02/22/2007] [Indexed: 12/01/2022]
Abstract
Novel monodisperse cationic pH-responsive microgels were successfully prepared by dispersion polymerization in ethanol/water mixture using N,N'-dimethylamino ethyl methacrylate (DMAEMA) as the monomer, poly(vinyl pyrrolidone) (PVP) as the steric stabilizer and N,N'-methylenebisacrylamide (MBA) as the cross-linker. The effects of various polymerization parameters, such as medium polarity, concentration of cross-linker, concentration of monomer, and concentration and molecular weight of stabilizer on the final diameter and monodispersity of poly(N,N'-dimethylamino ethyl methacrylate) (PDMAEMA) microgels were systematically studied. The pH-responsive characteristics of PDMAEMA microgels were also investigated. The experimental results showed that these microgels exhibited excellent pH-responsivity and significantly swelled at low pH values. The maximum ratio of volume change of the prepared microgels in response to pH variation was more than 11 times. It was found that the prepared microgels completely aggregated at the isoelectric point (IEP) around pH 6. On the other hand, the microgels were stable in aqueous solution at both low and high pH values. The results can be used for effectively controlled separation of particles.
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Affiliation(s)
- Lin Hu
- School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, PR China
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40
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Bajomo M, Steinke JHG, Bismarck A. Inducing pH Responsiveness via Ultralow Thiol Content in Polyacrylamide (Micro)Gels with Labile Crosslinks. J Phys Chem B 2007; 111:8655-62. [PMID: 17550282 DOI: 10.1021/jp070491a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Here we present the synthesis and characterization of pH responsive polyacrylamide microgels, synthesized via free radical polymerization of acrylamide and bis (acryloylcystamine) (BAC). The gels were made with ultralow amounts of thiol functional groups incorporated into the polymer. The resulting gel monoliths were mechanically chopped into microgel particles with size distributions ranging from 80 to 200 mum. The gels exhibit an interesting reversible pH-dependent rheological behavior which led to gelling of the colloidal suspension when the pH was increased, and a low-viscosity suspension was obtained when the pH was taken back to the original value. The viscosity of the colloidal system containing MBA crosslinked microgels remained insensitive to pH. This observation motivated further analysis; viscosity measurements of the highly viscous (gel-like) state of the BAC crosslinked microgel colloidal suspension were carried out to further understand the rheological behavior of the colloidal system. Electrophoretic mobility measurements as function of pH of the BAC and MBA crosslinked colloidal polyacrylamide microgel suspensions were performed. The swelling behavior of the microgels for both colloidal systems was also determined as function of pH using static light scattering. This swelling behavior was used to rationalize the observed rheological behavior. The work presented here demonstrates that free thiol groups present within a polymer gel matrix confer pH responsive behavior to the gel in solution. The viscosity of a BAC crosslinked microgel suspension was also measured under reducing conditions. The viscosity of the microgel suspension reduced with time, due to the breakage of the disulfide bonds in the crosslinkers.
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Affiliation(s)
- Michael Bajomo
- Department of Chemical Engineering, Polymer & Composite Engineering (PaCE) Group, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
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41
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Niu J, Shi F, Liu Z, Wang Z, Zhang X. Reversible disulfide cross-linking in layer-by-layer films: preassembly enhanced loading and pH/reductant dually controllable release. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:6377-84. [PMID: 17441740 DOI: 10.1021/la063670c] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This paper describes the fabrication of polyelectrolyte multilayer film which combines preassembly of poly(allylamine hydrochloride) (PAH) and 5,10,15,20-tetraphenyl-21H,23H-porphine-p,p',p' ',p' ''-tetrasulfonic acid tetrasodium hydrate (TPPS) in aqueous solution with the layer-by-layer (LbL) assembly of the PAH-TPPS complex and cross-linkable polyelectrolyte, PAASH60, which is a poly(acrylic acid) with 60% of its carboxylic acid grafted of thiol groups. During preassembly, TPPS was incorporated into PAH chains. After oxidative cross-linking to form disulfide bonds in between the layers, the multilayer with preassembly of the PAH-TPPS complex allowed for release and loading of TPPS in a reproducible way. The release of TPPS from the loaded film was a pH-controlled process. To compare with the conventional multilayer, the reloading capacity was greatly enhanced, which was related to the charge binding sites that formed by release of TPPS from the multilayer. Moreover, the release of TPPS could also be achieved by breaking off the cross-linking through reduction of disulfide bonds, and the release rates could be controlled by the reductive efficiency of the reductants in the media. In this way, the release of TPPS is pH/reductant dually controllable, thereby facilitating a new route to multistimuli controllable materials.
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Affiliation(s)
- Jia Niu
- Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 100084, Peoples' Republic of China
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Gu J, Xia F, Wu Y, Qu X, Yang Z, Jiang L. Programmable delivery of hydrophilic drug using dually responsive hydrogel cages. J Control Release 2007; 117:396-402. [PMID: 17239981 DOI: 10.1016/j.jconrel.2006.11.029] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 11/09/2006] [Accepted: 11/28/2006] [Indexed: 11/25/2022]
Abstract
Micro-capsules normally encapsulate therapeutic agents only inside their cavities. In this paper, we report on the synthesis of dually responsive poly(N-isopropylacrylamide) (PNiPAM)-co-acrylic acid (AA) hydrogel cages sub-micrometer in size and the use of these cages as drug carriers. The cavity structure of the cages can enhance volume phase transition compared to solid gel particles, thus favoring drug loading and release. TEM images and FT-IR spectra confirmed that the model drug isoniazid (INH) is located in two regions: within the shell and inside the cavity of the cages. The drugs residing in the shell can form hydrogen bonds with the cage matrix, while the drugs in the cavity are interaction free with the carrier. This difference from the residency of drugs exploited to a structure induced drug release which was programmable controlled by external pH and temperature. In vitro drug release studies showed that in a neutral medium (pH=7.4), major drugs were preserved within the shell, while in an acidic medium (pH=1.2), nearly all of the drugs were released due to the dissociation of hydrogen bonds.
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Affiliation(s)
- Jingxia Gu
- State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
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Abstract
A novel approach toward improvements of oral chemotherapeutic formulations has evolved, which combines solubilisation (molecular dispersion) of the hydrophobic anticancer drugs in micelles attached to large macromolecules or microparticles. The large size of the macromolecules or microgels prevents the gel components from being transported into the systemic circulation. The discussed gels comprise copolymers of poly(acrylic acid) (PAA) and Pluronic surfactants, linked via C-C bonds. The Pluronic-PAA copolymers are non-irritating when administered orally. The micelles formed in the Pluronic-PAA solutions and in crosslinked microgels can be loaded with chemotherapeutic drugs and then released in contact with the intestine. The microgels are collapsed at the acidic pH of the stomach and expand, thus releasing the loaded drugs at the pH of the lower gastrointestinal tract. Yet the microgels are mucoadhesive and enable longer retention time and prolonged release in the colon. Ease of preparation and formulation of the drugs with the Pluronic-PAA polymers and gels may enable the wider use of oral chemotherapy, resulting in a better patient compliance and improved quality of life of the patients.
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Affiliation(s)
- Lev Bromberg
- Massachusetts Institute of Technology, Department of Chemical Engineering, Cambridge, MA 02139, USA.
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45
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Li C, Madsen J, Armes SP, Lewis AL. A New Class of Biochemically Degradable, Stimulus-Responsive Triblock Copolymer Gelators. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200600324] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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46
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Pong FY, Lee M, Bell JR, Flynn NT. Thermoresponsive behavior of poly(n-isopropylacrylamide) hydrogels containing gold nanostructures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:3851-7. [PMID: 16584266 DOI: 10.1021/la0534165] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We report the changes in the structure and thermoresponsive behavior of poly(N-isopropylacrylamide) (PNIPAm) hydrogels when gold nanostructures are synthesized in situ within the hydrogel matrix. Cross-linked PNIPAm hydrogels were synthesized using NIPAm and 0.00-3.50% (w/w versus NIPAm) of N,N'-methylenebisacrylamide (MBAm) and/or N,N'-cystaminebisacrylamide (CBAm) as cross-linking agents. The hydrogels were soaked in potassium tetrachloroaurate to introduce gold ions. The hydrogels containing Au3+ were then immersed in a sodium borohydride solution to reduce the gold ions. Infrared spectroscopy, UV-visible spectroscopy, and equilibrium swelling were used to examine the structural/physical differences between gels of different compositions; UV-visible spectroscopy and mass measurements were used to observe the kinetics and thermodynamics of the hydrogel volume phase transition. These studies revealed several differences in the physical characteristics and thermoresponsive behavior of hydrogels based on cross-linker identity and the presence or absence of gold nanostructures. Hydrogels with gold nanostructures and high CBAm and low MBAm content have equilibrium swelling masses 3-20 times their native analogues. In comparison, gold-containing hydrogels with high MBAm and low CBAm content have swelling masses that are equal to their native analogues. Additionally, the gold-containing PNIPAm hydrogels cross-linked with only CBAm have a deswelling temperature of approximately 40 degrees C, approximately 8 degrees C above the samples cross-linked with only MBAm. Varying the CBAm content and introducing gold enables tuning of the deswelling temperature.
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Affiliation(s)
- Frances Y Pong
- Department of Chemistry, Wellesley College, 106 Central Street, Wellesley, Massachusetts 02481-8203, USA
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Ulanski P, Pawlowska W, Kadlubowski S, Henke A, Gottlieb R, Arndt KF, Bromberg L, Hatton TA, Rosiak JM. Synthesis of hydrogels by radiation-induced cross-linking of Pluronic® F127 in N2O-saturated aqueous solution. POLYM ADVAN TECHNOL 2006. [DOI: 10.1002/pat.824] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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